Why are permanent magnet motors more energy efficient?

Editor:浙江汇迅骏机电技术有限公司 │ Release Time:2020-08-13 

Permanent magnet motor is a kind of motor whose rotor has permanent magnet. It has many advantages of reliable operation, small size, light weight, small loss, high power, belonging to the super efficient motor.  The energy saving effect of permanent magnet motor is very significant than that of asynchronous motor, what is the reason? 


Firstly, from the perspective of planning and structure method, the rotor of permanent magnet motor has rare earth permanent magnet steel, which does not need stator to supply induction electricity;  Permanent magnet motor using star wiring Y, asynchronous motor 4KW above the motor is  connection, Y connection than  connection current is small;  Permanent magnet motor using different materials, high insulation grade, on the premise of maintaining the same power, can reduce a frame number, copper consumption reduction, permanent magnet motor control function is good, can adjust the start torque, satisfied with the big torque start, and then reduce the motor model, to prevent the situation of the big horse car. 


Secondly, from the actual use of the situation, the no-load current of the permanent magnet motor is only about 1/3 of the asynchronous motor, reducing consumption; When dragging equipment to a stable flow, pressure, active control system will be active conditioning, current will be reduced or in reactive state; In the running process of permanent magnet motor, when the load changes, the energy efficiency value can stick to the same, and when the load changes, the energy efficiency value of asynchronous motor will change. The energy efficiency of induction motor will not change when the load reaches 3/4, but will decrease linearly when the load is less than 70%.